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Old 05-31-2013, 07:42 PM
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DaveInDenver DaveInDenver is offline
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Join Date: Jun 2006
Location: Larimer County
Posts: 6,587

That chart is probably overly dramatic (and they conveniently sell tranny coolers), but the fundamentals seems true that you don't want the ATF going beyond about 225°F.

The thermal expansion coefficient of materials is constant, most aluminums being about 12 to 13 ppm (e.g. microinch) per °F and irons are typically about 6 to 7. My main worry would be ruining the fluid more than the marginally worse metal expansion. Joining dissimilar metals is a bad idea but unfortunately common on our junk.
'91 Toyota Pickup
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“Anyone who believes in indefinite growth in anything physical, on a physically finite planet, is either mad or an economist.” -- Kenneth E. Boulding

Last edited by DaveInDenver; 05-31-2013 at 08:06 PM.
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